hooven



July 18, 1950 F. J. HOOVEN 2,515,370

HIGH ENERGY IGNITION SYSTEM Filed June 5, 1948 2 Sheets-Sheet l Fire 0 0 BREAKER 55 SWITCH 2r ATTORNEYS July 18, 1950 F. J. HOOVEN 7 HIGH ENERGY IGNITION SYSTEM Filed June 5, 1948 2 Sheets-Sheet 2 STARTING MOTOR O 20 30 BREAKER55 SWITCH?! IN VEN TOR.

ATTORNEYS Patented July 18, 1950 UNITED k 2515370 HIGH ENERGYIGNITION SYSTEM Frederick JLHooven, Dayton, Ohio ----A=pp1ica;nbnqime5, 1948, @Seria'l-;No. 31 ,sss-

This inventionrelates to ignition systems for internal combustionengines;

Theiprincipal object of the invention is to provide an ignition: system- :which is sirnple and economic. in construction and 'operation and which affords increased energy for the- -produc-'- tion of; thespark;

It is also an obj'ect to provide such anfig'hition system having a single bre'aker and: inwhich=the circuit through: .the induction coil is allowed to remain closed-for a longer period than" the:-i'ntervalibetween; successive operations of 'the breaker thus providing for-"a -substantially greater build-up of the current through the coil-' witha correspondingly increased spark energy when--the breaker opens.-

It is a further object to provide an ignition system having a single high tension -transformer and a. single breaken associated with aplurahty opt-induction coils which are included in the: cir cuit in successive overlapping relation: and: ar'- ranged. to have the current: therethrough build up for a longer; period of time thanthe interval .between operations of the breaker.

It is a still. iurther object to prov-ide such a system; in which. the current new throughathe breaker for each successivecroperation thereof takes-place inzthei opposite direction: thus promoting'z durability and longer life: for the breaker contacts.

It is also anxobject to'provideuanaignition isystem in which the:cir'cuit'is modified during' start- .ing. to provide: substantiall increased energy in the ignition circuit under theseconditions;

other objects and advantages will: be apparent from the following description; the. accompanying drawings, and the appended claims;

In-the: drawings: v

Fig. 1 is a diagrammatic showing ot-anignition system in accordance with the present invention.

adapted for an 8 cylinder engine;

. Fig. 2 is a timing diagram showing thesequence 'system inwhich provision is -made for increasing the spark energy durng the starting of the engine; and

Fig, 4 is a timing diagramshowingthe sequence of events in connection witha systemaadapted for a 12 cylinder engine. I s

In providing high tension sparkdmpulses-zfor the ignition system" of an internal combustion engine, a commonly used system includesan induction coiI energized from a lowvoltage di- 15 claims (01. 315 211) rect current s0urce,;such as a car battery. The timing. of. thesparks in such a system maybe efiected by wcam operated-contactor or breaker which interrupts the-circuit. between the primary cit-flow. tension side of thecoil or transformer andrthe battery. at the'iinstant the spark is de sired} and ordinarily re.-establishes thecircuit as soon-= thereafter as iswmechanically practicable. Theirapid change. in fiuxproducedby the-interruption ofhthesprimary current. causes the induction. of ahigh voltage in the secondary ofthe transformer which isutilized to produce a spark in the sparksplug. of theieng'ine, the spark being directedtothe proper plug and cylinder by means of a distributor, v

The electrica-L energy stored. in. the induction coilat theamoment. otitS-release maybe expressed as;

, 2 1) where -W is the: energy in jbulesi L the indiicz'tance"oithev coil inhe'nri'eaand 12 is the currentflowi'ng to the coil winding in ampere's.

A resistance R. is ordinarily included in. the cir- 'cuitih' order tolinilt the new r current through the coil to a roper-'va1ne, depending upon the voltagefE of the battery',.and the resistance within the" boil itself 'Wheh the circuit is established through the coil and battery the flow of current" thereafter is expressed by In 'highspeed multi-cylinder engines, the inductance of the coilcLi's'limited' to that Value at which tne'currentwiu' rise to aworki'ng value in .the availabletiine when the. engine is running at its maximumespeed. .w-Assum-ingian B- cylinder'engine rotating. at awcrank shaft speed. ofl ljQO R; andacam shaft speed of. 2,250. R.. P.

and assuming the duration of thevclosure of. the

breaker is 305 oilcamshaftlrotation,v the time T availableior the. increase of current in the coil will be approximately .0022 second. On the assumption that a current of such a system will then be 1;

ioule per spark and this only at speeds so low" that i is substantially equal to AI /4,500

R. P. M. such a system will produce only half the maximum energy, or .0135 joule.

In current motor car engines, where multiple cylinders are the rule, engine speeds arehigh, wide spark plug gaps are" usuallyprovided to facilitate smooth running, and battery voltages are usually limited to about 6 volts. Whenever, because of high engine speed or a large number of cylinders, more sparks per second are required then a single coil system 'will' provide, or where by virtue of wide plug gaps or a high compression ratio a-larger energy per spark isdesired, it is customary to use a double coil system, such as the duplication of the entire ignition system, one part being used for each half of the engine. In addition to materially increased cost, such an arrangement has the disadvantage that it requires synchronization of the'two systems to afford uniform timing for the entire engine;

In accordance with'the present invention'the energy output of a two coil system is provided while retaining the. advantage that the entire timing operation of the engine is accomplished by a single breaker so that there is no necessity for synchronizing two separate systems. 1" Eur,- ther, the arrangement is such that there is a substantial saving in the high tensio'r'iitransformer and distributor commonly used with double coil systems, only a single such transformer being required, and .it' being of different, and less expensive, construction than that em.- ployed in the double coil systems. The'jcircuit arrangement is further "such that the," single breaker which controls the timingof tl'ife'spark impulses is arranged so that alternate breaks are of opposite polarity, this feature bein g'favorable to prolonging the life of the coma-ermine.

Thus the system providesfor more reliable and efiective ignition throughout the entire range of normal running of the engine and particularly at the higher speed ranges where a full and adequate spark is maintained. The invention also provides improved ignition characteristics when the engine is operating at slow speed, and particularly when it is being under such conditions may be substantially increased without increasing the current flow through the breaker and thus without overload- A ing the breaker contacts. With the same current now, a substantial increase in spark energy is provided, so that adequate sparking voltages are assured, thus greatly facilitating the starting of the engine. When the engine speeds up, or when the starting operation is terminated, the circuit conditions are restored to their original condi tion, the system thus providing for increased spark energy at low speed, as well as when operating at high speed. t

ji Refe'rrin'g to'the drawing, Figs. 1 and 2 illustrate anembodiment of the invention suitable for providing ignition energy for an 8 cylinder engine. The battery is shown at It], .the ignition switch at H and the two induction coils I2 and I3, both of which are supplied with energy from the battery. Coils l2 and I3 are connected respectively through current limiting resistors 14 and I5 with cam operated switches shown i generally at 20 and 2|.

v These switches include multiple contacts 22 and 23 cooperating respectively with fixed contacts 24 and 25, the latter being connected together and to the opposite side of battery l0 throughwire 26. A cam shown as having 4 lobes spaced 90 apart 'is arranged to actuate the switches 20 and 2|, the switches being located in such relation to the cam and to each other that they. operate alter- ,nately, with an opening movement of each such switch occurring every 'of revolution of cam 36. It will be. understood that cam 30 is driven from a shaft 3| which may be the usual timing shaft, of the. engine, such as the engine cam shaft, or a shaft operated in direct relation thereto. i

Cam shaft 3! also carries an 8 lobed cam 35 which is arranged to actuate the breaker 35 shown as having a movable point 3? and a fixed switch point 38. Fixed switch point 38 is shown as connected tothe'movable contact 22 of the cam operated switch 20 by wire lflwhile movable switch point S'Iis shown as connected to the'movable contact 23 of, cam operated switch The secondary or high tension winding 48, of the transformer is connected at one side toground as shown at 49, and its'other. terminal is connected through. the distributor which is mounted on and driven from the cam shaft 3i, in order 2to' distribute the high tension spark :impulses selectively through distributorpoints 5| -to..the-proper spark plugs 52, in the usual manner.

The switches 20 and ZI' are shown'as so arranged that they open alternately prior to the 'openingbreaker points 37, 38 and close alternately'after the closing of the breaker contacts; the arrangement also is such that switches 20 and 2| are never both-open at the same time. The sequence 'ofevents-and the timing of the system is as shown in the timing diagram of Fig. 2 in'which theenergization of the respective coils l2 and I3 and the times-of closing and remaining closed of the switches 20 and 2 I and of breaker 35 is indicated by the presence of a solid arcuate line, the deenergization of the coils or opening of the switch contacts being indicated as occurring at the point wherethe solid arcuate line ends.

In operation, and with the parts in the position shown in Fig. 1, breaker 35 has just opened its contacts-31, 38, and on the timing diagram this position' is indicated by the vertical line -marked The opening of contacts 31, 38' has resulted in breaking the circuit through coil I3, switch contacts 23, 25 having already opened. Thecircuitthrough coil I2 is closed through 'switch contacts 22, 24 but there is no circuit to .continue the flow of battery current through coil I3, the only circuit for the discharge of the energy'therein being through condenser 43 and the primary 45 of the transformer. Thus the interruption in the circuit results in a surge of current through primary winding 45 of the transformer producing a high voltage spark in the secondary 48 which is thereupon distributed to the spark plug 52. At the same time, switch 20 being closed, a charging circuit isv maintained from battery I0, through switch I I, inductance 1c'oilI2, resistor I4, the contacts of switch 20, and through wire 26 to the other side of the battery ,so that the current is building up in coil I2 not.- withstanding the opening of the breaker 35. v In the next interval, shown as occurring at about 15, breaker 35 recloses its contacts and thereupon a circuit is established for the flow of charging current through coil I3, this circuit being from battery I0, through switch II, coil I3 and resistor I5, wire 4|, contacts 31, 38, wire 40, contacts 2224 of switch 20, and through wire 36 to the other side of the battery. Thus at'this .time and for the next interval, a charging current is maintained through both coils I2 and I3. At a somewhat later interval, shown as at about 25, switch 2| closes its contacts 23, 25, but this does not produce any change in the circuit since it merely establishes a parallel energizing path for the induction coil I3.

Subsequently, and at approximately 35, switch 20 opens its contacts 22-24, but this likewise does not produce any change in the circuits, the current continuing to flow through both induc- ;tion coils I2 and I3, the circuit being maintained through breaker contacts 31 and 38. The circuit for energizing coil I3 is directly through contacts v23, 25, while the circuit for the energizing of coil I2 is through wire 40, breaker contacts 31, 38, wire 4| and contacts 23 and 25. The current is thus allowed to build up over an extended period of time in coil I2, the total interval in the arrangement shown being about 75.

At a position shown as the 45 point, and after remaining closed for approximately 30, the breaker 35 opens its contacts 31, 38, thereby abruptly breaking the circuit through coil I2. This produces a heavy surge ofcurrent which .flows through the primary 45 of the transformer, producing a high energy spark in the same manner as described above, such spark being distrib- .,uted to the next point of the distributor for delivery to the proper plug 52. The flow of charging current through coil I3 however is not interrupted but continues until the next operation of the breaker.

are not themselves required to control the flow :of the current. Therefore they are subject to onlylimited wear and burning, and may be of relatively inexpensive construction.

1 [The control of the current is handled entirely by contacts 3'! and 38 of breaker 35, and it will be further evident that with each alternate operation of the breaker, the current is flowing in the opposite direction through its contacts. This is advantageous as avoiding objectionable burning, and further contributes to prolonged life and reliability of operation. With the breaker 35 re- 'maining open for about 15 of rotation and being closed for about 30 of revolution, the charging circuit through each of coils I2 and I3 is nevertheless maintained closed over much longer intervals, approximately of the order of 75, and a correspondingly longer time and increased build up of current flow in the system is therefore provided.

By connecting transformer 46 across contacts 31, 38 of the breaker, and across condenser 43, the energy of the induction coil circuit is converted to high tension energy in a highly efiicient way, and in the same manner as if a high tension winding Were placed on the same core as the induction coil itself. By utilizing the transformer 20 in the manner shown, it is possible to convert the energy of each of the two induction coil circuits in sequence, thus requiring only a single high tension winding, which is the most expensive part of the coil. Further, it is possible to utilize less material in this winding than would be required for the high tension winding of an induction coil because it is wound on a magnetic core which is not utilized for energy storage and which may therefore be formed without air gaps.

As a specific example, coils I2 and I3 may each be wound with 250 turns of wire on an open core consisting of a bundle of iron wire inch in diameter and 3 inches long. Primary winding 45 of the transformer may comprise 50 turns of wire on a closed core, while secondary 48 may contain 6,000' turns wound directly over primary 45. Resistor 4'l is chosen so that its resistance, in addition to that of primary 45, is approximately equal to the combined resistance of resistor I4 and coil I2, or that of resistor I5 with I coil I3. It is also practicable to embody enough resistance in each of the abovementioned coils by suitable choice of wire size so that resistors I4, I5 and 4'! are not required as physically separate components.

By comparison, a secondary or high tension winding wound as a part of coils I2 or I3 would require approximately 30,000 turns of wire to give the same voltage as that provided by high tension Winding 48, and in order to obtain the advantages as to prolonged time of charging, two such windings would be required.

Breaker 35 may be of comparable construction with the breakers used with a single coil system, points 31 and 38 being suitably formed of tungsten having diameters of from about .150 to .190 inch and a contact pressure when closed of about 16 to 20 ounces. Condenser 43 is likewise conventional, having a capacity of from .15 to .30 'microfarad. Since the contacts of switches 20 and 2| do not interrupt any appreciable flow of current, the contact points 22 to 25 may be of silver or other high conductivity material, requiring a smaller amount of material in the contacts and a lower contact pressure, so that the contactors may be of lighter and cheaper construction. It is also noted that the exact moment of opening and closing of switches 20 and 2| is not critical in the operation of the system so that their adjustment, and the effect of wear in use, do not present serious operating idifllculties.

amasvo When starting an engine withv a starter motor and an ignition coil operated .from the same battery, severe conditions often result in a failure to provide adequate sparking voltage and the spark plugs, due, to the engine being cold, the battery charge being low, the spark plug gaps being. widely separated, or a combination of such conditions. If it is attempted to increase the available ignition energy under such conditions by cutting out a part of the current limiting resistance to increase the current in the induction coil, this results in overloading the breaker contacts and may cause premature failure thereof.

In accordance with the present invention a System is provided for substantially increasing the ignition energy without increase of current under starting conditions by rearranging the circuit to include both induction coils in series for each spark. At low operating speeds adequate time is available for the buildup of current in the system sothat the energy may be increased by increasing the value of L in Equation 2 above.

Such an arrangement is shown in Fig. 3 in which parts having similar reference numerals are the same in construction and function as those described in connection with Fig. 1.

In addition, the starting motor is shown at 6B which is operated under the control of the starter switch 6| to cause the cranking of the engine. The closing of the starter switch also closes a circuit from battery II! through the actuating coil 64 of a relay, causing it to attract its armature carrying switch arms 65 and 66, to shift from the position where they are in contact with switch points Gl and 68 respectively when the relay is deenergized, to the position where they are in contact with switch contacts 69 and m respectively when the relay is energized.

Analysis of the circuit will show that when starter switch BI is open and relay 64 deenergized, the circuit is connected in the manner already described with respect to Fig. 1, with the induction coils being caused to be included in circuit with the transformer alternately in the manner already described. However when the switch GI is closed and relay 64 energized, a circuit is established from battery Ill, switch arm 66, contact 10, contact 67, and from there through coils I3 and 12 in series under the control of breaker .35, the circuit then being completed through wire 12 to resistor Is and battery I I]. A parallel circuit from coil I2 passes through wire I3, switch point 69 and switch arm 65, through resistor I5, and back to the other side of the battery. This arrangement provides for maintaining the same overall resistance in the circuit during the series or starting connection as in the running connection. Thus when connected for sequential operation, resistors I4 and I5 are included respectively in the energizing circuits for induction coils I2 and I3. Assuming for example the resistance ofeach induction coil I2 and I 3 to be R and that of resistors I4 and L5 to be 2R, then the resistance of each separate coil circuit when connected sequentially, will be 3R. On starting, the resistance Of the coils in series will be 2R while that of the resistances M and I5 in parallel will be B so that the total resistance in the series starting circuit will become 3R, and thus comparable or equal to that during the running condition.

The system thus provides for approximately double the energy of the spark during the starting period, but without requiring any materially 'ment and repair.

greater current flow, .or requiring increasedcurrent to be handled by the various switchmechanisms.

The system above described providesforbuildup of the currentin each of the induction .coils l2 and J3 for :a period of about 75 of cam shaft rotation, where the breaker remains open for only about 15 of cam shaft rotation, such interval being about the minimum period practicable mechan'ically at high operating speeds. With an 8 cylinder engine, this arrangement thus provides about two and one-half times the time available with a simple single coil system, and therefore provides for a value of L of about two and one-half times as large as with a single coil system providing a comparable increase in the energy for each spark. A further increase in time for the current build-up and corresponding increase in spark energy may be obtained by changing the relationship between the timing of the switches 20 and 2| with respect to breaker 35 to provide for the closing of the respective circuits through coils l2 and I3 through switches 20 and 2 I, respectively, rather than through the breaker contacts '31, 38. This provides for further reducing the opening time and increasing the time during which the charging current flows through each coil in the circuit.

Such an arrangement is illustrated in the timing diagram in Fig. 4 which is shown by way of example as applied to a 12 cylinder engine. As shown in the arrangement of Fig. 4, the cam 39 is similar except that it has siX lobes while cam 35 has. 12 lobes. The relationship of the two cams on shaft 3i is shown as such that switches 20 and ill close respectively about 5 after the opening of breaker 35, thus closing the energizing circuit in each instance at switch 20 or 2I, as distinguished from having the circuit closed upon the closing of breaker contacts 37, 38. The breaker itself closes at about 15 and therafter, at about 20, switch 2I opens its contacts, preparing for the break inthe circuit. through induction coil I3 at the next following opening of the breaker which occurs at about the 30 point, the energizing circuitsfor the two coils being thereafter completed alternately and in overlapping sequential relation to each other, throughout the complete cycle of operation of the system. This provides an additional closure time for each coil, making it possible to have the charging circuit closed through each-coil for a total of about 55 of cam shaft revolution, making possible a substantial increase in inductance and a corresponding increase in available spark energy, in comparison with a conventional system.

The invention thus provides a simple and highly advantageous ignition system for internal combustion engines which assures the development of a high energy spark at high speeds, comparableto that obtainable at low speeds, and by means of equipment which is relatively inexpensive and which is readily maintained in operating adjust- High energy is maintained throughout the normal range of speeds; up tothe maximum speed at which the engine will operate, and there is no material reduction or loss of energy as the speed reaches its maximum. Further, the invention assures an increased spark energy during the starting condition, while maintaining the same current flow and thus assuring proper and reliable operation of the entire mechanism throughout all conditions of operation.

While the methods and forms of apparatus herein. describedconstitute preferred embodi- 1. In an ignition system,:the combination of apair of induction coils; a pair of switches, means connecting said switches :in separate circuits through said induction coils with a source of elec-' trical energy. a breakerfmeans connecting said breaker to both'of said switch means, a hignvo1tage transformer having its primary connected across said breaker and its secondary adapted to supply a high Voltage ignition circuit,means'-for operating said switcnmeans alternately to cause energization of said two induction coils "at in tervals with the intervals of energization for one coil overlapping those for the other, and means for operating said breaker at twice the frequency of said switch means to break the energizing-ch1 cuit through each of said induction coils at'said breaker to provide for energizing the primary of said transformer.

2. In an ignition system adapted to be supplied from a source of electrical energy, the combination of a pair of induction coils, a breaker, a pair of switch means, means for operating said switch means alternately. means connecting said breaker in circuit with each. of said induction coils through said switch means to establish an energizing circuit from said source through said induction coils alternately upon each successive closing of said breaker, means for breaking said energizing cir cuits alternately upon each opening movement of said breaker, and a high tension transformer connected across said breaker for energization thereby upon each opening operation'ythereof.

3. In an ignition system adapted to be supplied from a source of electrical energy,"the combination of a pair of induction coils, a breaken an energizing circuit for each one of said coils, switch means in said energizing circuits providing for closing said circuits alternately through a1- ternate ones of said coils upon the closing of said breaker, switch means in said circuits providing for alternate opening thereof upon each opening operation of said breaker, and a high tension transformer having its primary connected across said breaker for energization upon each opening of said circuits.

4. In an ignition system adapted to be supplied from a source of electrical energy, the combination of a pair of induction coils, a breaker, an energizing circuit for each one of said coils, switch means in said energizing circuits providing for closing said circuits alternately through alternate ones of said coils upon the closing of said breaker, switch means in said circuits providing for alternate opening thereof upon each opening operation of said breaker with the opening of each one of said circuits following the closing of the other said circuit, and a high tension transformer having its primary connected across said breaker for energization upon each opening of said circuits.

5. In an ignition system, a high voltage transformer having a primary and a secondary, a pair of induction coils, a single breaker in circuit with both said induction coils and with the primary of said transformer, switching means for controlling the energizing circuit for one of said induction coils to establish a flow of current through said breaker in one direction, switching means 10 for'controlling the energizing circuit for the other of said coils to establish a flow of current through said breaker in the opposite direction, and means for breaking the flower current to each said coil at said single breaker;

'6. In an ignition system, a high voltage transformer having a primary and a secondary, a pair of induction coils, a singlebreaker in circuit with both said induction coils and with the primary of saidtransformer, switching means for controlling the energizing circuit'for'one of said induction coils to establish a flow of current through said breaker in one direction, switching means-for controlling the energizing circuit for the other'of said coils to establish a flow of current through said breaker in the opposite direction, means for closing the energizing circuit for oneof said coils prior to the opening of the circuit for the other said 0011, and means for breaking the flow of current'to each said coil at said single breaker.

7. An ignition systemfor use with an internal combustion engine comprising. a high tension transformer, a distributor on the high tension side of said-transformer, a 'hreaker on the low tension side of: saidtransformer, a plurality of induction coils, switch'zmeans'for establishing a charging circuit through each' of said induction coils in sequence and for maintaining said circuit closed'for a period of -time greater'than the interval of each'saidr operation of said breaker,

and means for successively including each of said coils in circuit withsaid breaker to provide for the breaking of the circuit through said coils and through the low tension side of said transformer sequentially, at the same'isaid breaker at each successive operation thereof.

8. 'An ignition system for an internal combustion engine whichcomprises a high tension transformer, a distributor in the high tension winding of said transformer, 'a-bre'aker' in the low tension winding of said transformer, at least two induction coils, switch means" for establishing a circuit through the primary of said transformer and through said induction coils in sequence during normal running of said engine, and controllable means for including said induction coils in series for increasing the energy developed by said transformer during starting.

9. In an ignition system system for an internal combustion engine, the combination of a pair of induction coils adapted to be energized from a source of energy, a high tension transformer having a primary and a secondary, a single breaker, means for alternately including each said induction coil in an energizing circuit with said primary providing for greater time of closing of said energizing circuit through each said induction coil than the interval between operations of said breaker, and means for breaking the circuit through each of said coils alternately at successive operations of the same said breaker.

10. In an ignition system for an internal combustion engine adapted to be energized from a source of energy, the combination of a plurality of induction coils, a breaker, a high tension transformer, means for establishing a charging circuit through one said induction coils and said transformer, means forming a concurrent charg ing circuit through the other of said induction coils, means including said breaker for breaking the charging circuit through the first said coil, means providing for maintaining said charging circuit through the other of said induction coils, and means including the same said breaker for H breaking the circuit, through said; other induction so in timed relationship: with the breaking of said first charging circuit.

1.1. The method of providing high energy spark ignition in an ignition system oi an internal combustion engine which comprises storing to maintain such flow of current therethrough for a period longer than. the interval. between sparks, and breaking the circuit through each of said coils in sequence and in accurately timed intervals at the same point.

12. The method of providing high energy spark ignition in an ignition system for an internal. combustion engine which comprises: supplying energy toa pair oi induction coils in. over lapping: sequential relation to each. other, maintaining the energizing circuitto each said coil for a. period longer than the interval between successive sparks, breaking the circuit through said coils alternately and inaccurately timed relation at the same point to produce a high energy charge, and supplying said high energy charge to av high tension transformer.

13.. The: method of providing high energy spark ignition in an. ignition system for an internal: combustion engine which comprises sup-- plying energy to a pairof induction coils in overlapping sequential relation to each other, breaking the circuit through said. coils in. alternate relation to produce a high energy charge, supplying said, high energy charge to a high tension. transformer, and reconnecting the two induction coils; in series: during the starting of' the engine.

14. In an ignitionv system for an internal combustion engine; adapted tobe energized from a source of energy the combination of a pair of induction coils, a breaker, a high tension transiormer, switch means for sequentially connecting said induction coils to said energy source in overlapping energizing relationto each other to provide increased time for the build-up of the energy therein, means for including each said coil. alternately in circuit. with said breaker and with said high tension transformer to produce aenergy surge through saidv transformer under the control of said breaker, and means for breaking. the circuit through each said coil. inv accurately timed intervals at the same said breaker..

15. In an ignition system for an. internal combustion engine" adapted to beenergized from a source of energy the combination oi. av pair of induction coils, a breaker, a high tension transformer, switch means for sequentially connecting said. induction coils to said energy source in overlapping energizing relation to each other to provide increased time for the build-up of the energy therein, means for including each said coil alternately in circuit with said breaker and with said high tension transformer toproduce a high. energy surgethrcugh said transformer under the control of said breaker, and controllable means for connecting said induction coils in se-- ries to provide: increased spark energy for starting;

FREDERICK J. HOOVEN.

REFERENCES. CHPED The fol-lowing references are of record in the 

